| As everyone knows, adjustment ways of the air flow for fans are mainly man-made ways:adjusting damper,baffle, valve opening size and so on.The artificial adjustment ways, not only the control precision is low, can’t always make the air flow of fans in the right size at real time, but also waste a large amount of electrical energy, electrical energy efficiency is generally low. In the new field, the variable frequency variable speed (i.e., frequency control technology), by changing the current frequency to change the motor’s speed, realize the no-pole speed regulation, to achieve actual needs of motor speed, so as to adjust volume size, to achieve energy saving effect.In response to the Ministry of National<motor energy efficiency improvement plan (2013-2015)>,the objectives of the motor enterprise is to manufacture a high efficiency and energy saving motor.Permanent magnet synchronous motor has a volume of space high efficiency, high power factor,good performance of speed adjustment, which accounted for a small, is a kind of high efficiency and energy saving motor ideal.The permanent synchronous magnet motor has the advantage of high efficiency,was favored by the majority of production enterprises, universities and research units.But inherent problems are the electromagnetic noise and cogging torque,are the core keys to be solved.This subject comes from a wind machine enterprise of Foshan.It about the design and optimization of an outer rotor permanent magnet synchronous motor for fan, it has high efficiency,small vibration and low noise.Firstly,the paper introduces the knowledge of ANSYS finite element and the method to build a two-dimensional model of knowledge based on Maxwell2D.Then,we analysis several common slot pole match.such as 9 slot 6 pole、12 slot 8 pole、12 slot 10 Pole、15 slot 10 Pole.From the radial force wave aspects,we get the inherent problem is fraction slot with magnetic electromagnetic noise.From the two optimization aspects of the air gap flux density harmonic analysis and cogging torque, we choose the best slot pole combination with 12 slot 10 pole combination.It can reduce the cogging torque and weaken the harmonic content of air gap flux density effectively. Then we manufacturing a machine(original motor),it has large vibration and electromagnetic noise problems.To reduce the cogging torque from the optimal pole arc coefficient magnet and optimize the magnetic field waveform of air gap from the magnet of the eccentricity, we can get the optimum magnetic pole arc coefficient and eccentricity. The finite element analysis and comparison between the original motor and the new motor, the result is that the new motor’s output torque fluctuation is smaller and the air gap harmonic is smaller, No-load back electromotive force more close to sinusoidal than original one.The results of the analysis is that the new motor’s electromagnetic noise vibration has much lower noise than original one in theory.Finally, we manufactured a new prototype accord to the size of the optimized parameters, and test it’s performance parameters and get the value of electromagnetic noise.We find it meets all the requirements when using the optimization design.In this paper, the performance and the Maxwell2D simulation of the prototype were analyzed, the correctness of the finite element analysis of Maxwell2D. This paper has certain engineering value and reference value. |
PDF Full Text Request